Review and stress-test launch messaging, landing pages, product announcements, p
Review and stress-test launch messaging, landing pages, product announcements, pricing pages, changelogs, app-store listings, and marketing emails before publication. LaunchCheck evaluates copy through eight audience lenses, surfaces positioning and conversion friction, flags claims needing evidence, predicts likely reader questions, recommends concrete changes, and returns a fact-preserving rewrite.
Not tested: has real-world effectsour last check, 2026-09-24
0 of 0checks answered this week
n/amedian answer time
$0.5listed price per call
n/aprice it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://launchcheck-x402.fly.dev/v1/reaction-check
| Category | Commerce and shopping |
|---|---|
| Provider host | launchcheck-x402.fly.dev |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
We never call tools that send, buy, move money or file anything, not even without paying.
Example input (from the provider)
{
"body": {
"constraints": [
"Do not invent metrics"
],
"content": "Stress-test launch copy before you publish. LaunchCheck reviews messaging through eight audience lenses, flags positioning friction and unsupported claims, and returns concrete changes plus a fact-preserving rewrite.",
"contentType": "landing-page",
"desiredAction": "Run a paid reaction check.",
"productContext": "An x402-paid API for structured pre-launch copy review.",
"targetAudience": "Founders, product teams, and AI agents."
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"properties": {
"constraints": {
"default": [],
"description": "Optional factual, legal, brand, or wording constraints that the review and rewrite must preserve.",
"items": {
"maxLength": 300,
"minLength": 1,
"type": "string"
},
"maxItems": 10,
"type": "array"
},
"content": {
"description": "Launch or marketing copy to review before publication, such as a landing page, product announcement, changelog, pricing page, app-store listing, or email.",
"maxLength": 12000,
"minLength": 40,
"type": "string"
},
"contentType": {
"default": "other",
"description": "Kind of copy being reviewed; use other when none of the listed categories fit.",
"enum": [
"landing-page",
"product-announcement",
"changelog",
"pricing-page",
"app-store-listing",
"email",
"other"
],
"type": "string"
},
"desiredAction": {
"description": "Optional action the copy should persuade the reader to take, such as sign up, start a trial, buy, upgrade, or learn more.",
"maxLength": 500,
"type": "string"
},
"productContext": {
"description": "Optional context about the product, feature, offer, or company needed to judge positioning, clarity, and factual fit.",
"maxLength": 2000,
"type": "string"
},
"targetAudience": {
"description": "Optional intended audience or buyer segment whose likely reaction should inform the review.",
"maxLength": 1000,
"type": "string"
}
},
"required": [
"content",
"contentType",
"constraints"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"properties": {
"meta": {
"additionalProperties": false,
"properties": {
"cached": {
"type": "boolean"
},
"engine": {
"type": "string"
},
"generatedAt": {
"pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:\\.\\d+)?(?:Z|[+-]\\d{2}:\\d{2})$",
"type": "string"
},
"model": {
"anyOf": [
{
"type": "string"
},
{
"type": "null"
}
]
}
},
"required": [
"engine",
"model",
"generatedAt",
"cached"
],
"type": "object"
},
"report": {
"additionalProperties": false,
"properties": {
"audienceReactions": {
"items": {
"additionalProperties": false,
"properties": {
"confidence": {
"maximum": 1,
"minimum": 0,
"type": "number"
},
"friction": {
"anyOf": [
{
"maxLength": 500,
"minLength": 1,
"type": "string"
},
{
"type": "null"
}
]
},
"lens": {
"enum": [
"Skeptical technical buyer",
"Busy nontechnical decision-maker",
"Price-sensitive solo user",
"Privacy and security-conscious evaluator",
"Existing customer scanning for regressions",
"First-time visitor with low context",
"Enthusiastic early adopter",
"Support-minded operator anticipating questions"
],
"type": "string"
},
"likelyThought": {
"maxLength": 500,
"minLength": 1,
"type": "string"
},
"reaction": {
"enum": [
"positive",
"mixed",
"negative"
],
"type": "st